Question

For an SCR the average & rms values of current are I/4 & I/2 respectively. Calculate the average on-state current rating (ITAV). Take maximum RMS on-state current = 35 A.

(a) 8.78 A

(b) 10.10 A

(c) 17.5 A

(d) 24.74 A

I had been asked this question in exam.

Enquiry is from Thyristor Ratings in division Power Electronics Devices of Power Electronics

Answer 1

The correct answer is (c) 17.5 A

Easy explanation: Form factor = RMS/Average vaules of current

Therefore, FF = 2

I^TAV = 35/2 = 17.5.